Diesel taxis are a well-documented major source of urban air pollution. LPG can clear up this fleet quickly and cheaply. The problem is national: tightened emissions standards under London’s forthcoming Ultra Low Emissions Zone means that already taxis unable to operate in London are displaced to cities with less stringent emissions standards.

In order to better demonstrate the environmental performance of LPG taxis, we have converted a TX4 diesel to run on LPG.

Independent testing showed that, when running on diesel, the TX4 was did emit worse than Euro 3 emission standards under real world conditions – despite the fact that the taxi, which is a 2010 model, should have been meeting Euro 4 standards.